Canine Blood Group Prevalence and Geographical Distribution around the World: An Updated Systematic Review

SIMPLE SUMMARY: “Blood group” or “blood type” refers to the blood group system comprising red blood cell antigens and a specific pattern. Many studies have characterized dog blood groups by the prevalence of the Dog Erythrocyte Antigen (DEA), Kai, and Dal antigens in different geographic areas and by using a variety of methods. Some pioneering studies on blood groups, upon which others were subsequently based, were conducted by Bowdler, Colling, and Hall in the 1970s and 1980s. Our results show that most relevant studies covered the European and American continents, and the methods used to identify DEA, Kai, and Dal groups evolved from 1999 to 2020, albeit without a single method based upon specificity and sensitivity. However, the existence of rapid commercial kits for the determination of the DEA 1 group makes this group the most widely used in clinical practice. Through a systematic review, our aim was to illustrate the countries in the world where different blood groups have been identified with reference to the different methods used and the prevalence of those groups among dog breeds. ABSTRACT: In recent years, blood transfusions have been more commonly given to pets. The importance of determining blood groups in dogs and cats is, therefore, well-known for reducing the risk of adverse reactions in the recipient blood caused by a “non-compatible” donor. This systematic review summarizes data from previously published reports and follows the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews. After applying the inclusion and exclusion criteria, we identified 41 eligible studies using different states and blood-typing methods to determine blood groups in dogs. The dog blood groups that were identified between 1999 and 2020 in 17 different countries were combined to yield the DEA (Dog Erythrocyte Antigen), Kai, and Dal groups. These studies were conducted in Europe, America, Africa, and Asia but not in all the countries of these continents. The methods used to determine blood types have also changed over the years. This systematic review highlights gaps in the literature and should advance future studies synthesizing data with methodological rigor.